1. Field of the Invention
The present invention relates to a circuit design inspection method, more particularly to a floating net inspection method.
2. Description of the Related Art
A netlist may be used when designing an integrated circuit, and is a file that describes in words a circuit structure of an application circuit. In order to make sure that the application circuit described by a netlist is operating normally, it is necessary to inspect for the presence of floating nets in the application circuit.
One way in which the presence of floating nets in an application circuit may be checked involves using a program included in an electronic design automation (EDA) tool. In particular, through use of such an EDA tool, a netlist of an application circuit is inspected to determine whether a gate of each metal-oxide semiconductor field-effect transistor (MOSFET) in the application circuit is connected to an element. If the gate is not connected to an element, the gate of the MOSFET is deemed to be floating. Although such a method allows for inspection prior to layout, it is not completely accurate. For example, when the gate of one of the MOSFETs is only connected to one terminal of a capacitor, the gate of the particular MOSFET is in a floating state, but is not determined to be floating using this conventional method. As another example, when the gate of one of the MOSFETs is only connected to one terminal of a resistor, although the determination of whether the gate of the particular MOSFET is floating depends on whether the other terminal of the resistor is floating, the conventional method will determine that the gate of the MOSFET is not floating regardless of the connection state of the other terminal of the resistor.